The Fender Pro-Tube "94 Twin" is a feature heavy beast that was the result of some Fender engineer deciding that the regular Twin just didn't weigh enough. Seriously, I'm pretty sure the cabinet is made of lead reinforced concrete. This particular amp was having issues with it's power tubes. The customer reported lots of snap, crackle, pops, and he wasn't wrong. It had been re-tubed and biased in the past, but those tubes soon gave up as well. I pulled the chassis from the cabinet expecting a long haul, but the problem was revealed almost immediately. The mounting hardware on half of the power tubes was missing. When played, the cabinet vibration was causing those two tubes to flap around wildly. I replaced the missing screws and applied thread lock to all the socket mounts. The amp didn't get any lighter, but it sure sounded better.